This invention relates to air guns for firing pellets and the like.
A variety of air guns for firing pellets and BB's are known including special air guns for firing paint pellets used in playing outdoor games. Such guns commonly employ a standard gas cylinder holding compressed gas which must be attached to or housed in a secure manner in the gun. In some guns a gas cylinder is arranged in the gun handle or pistol grip while in others it is attached to the rear end of the gun. The compressed gas from the cylinder is delivered to a gas valve system in the gun and compressed gas is released from this system in order to fire the pellet by a trigger mechanism.
Recent U.S. Pat. No. 4,531,503 issued July 30, 1985 to R. C. Shepherd describes a gas powered repeating pistol wherein the gas cylinder is stored in the handle portion. On the main frame of the pistol above the handle is a pressure chamber having a valve at its forward end. The barrel in this known pistol is slidably mounted and the hammer is located at the rear end of the pistol. Mounted on top of the barrel is a tubular magazine which can carry a number of pellets such as paint pellets. The pressurized gas is delivered to the pressure chamber from the gas cylinder through a short vertical tube mounted in the bottom wall of the pressure chamber.
Early U.S. Pat. No. 2,640,476 issued June 2, 1953 to L. K. Spink describes a pneumatic gun wherein the gas cylinder is mounted to the rear of the breech of a gun. The capsule is mounted in a holder in the form of a partial sleeve and it has a neck threaded for mounting on the rear end of a valve housing. The rear portion of this housing has a pointed pin for breaking the seal of a capsule as it is being mounted. The housing contains a central passageway that delivers the compressed gas to the valve unit of the gun.
Applicant's co-pending Canadian patent application Ser. No. 578,891 filed Sept. 29, 1988 and entitled "Air Gun" describes a gun for firing paint pellets wherein a hammer mechanism is mounted in a rear end of the pellet-firing barrel. The gas cylinder for this gun is mounted in an upper barrel mounted directly above and parallel to the pellet-firing barrel. This known gun has a gas valve system arranged in the lower barrel in front of the hammer. A hole extends between the two barrels and is located along a portion of the upper barrel that holds the gas cylinder. Compressed gas passes through this hole and into the gas valve system of the gun.
It is an object of the present invention to provide an air gun for firing pellets that has a unique breech having not only a main longitudinal passageway that contains the hammer mechanism and the gas valve system, but a smaller longitudinal passageway for compressed gas located at one side of the main passageway. This smaller passageway provides a reliable conduit for delivering compressed gas from a cylinder located at the rear of the gun to the gas valve system in the main passageway.
It is a further object of the invention to provide a breech for an air gun having its own passageway for compressed gas, which breech is relatively simple and inexpensive to manufacture.